Scale.



R. F. CHATILLON.

SCALE.

APPLICATION min APRA-1. |912.

1,251,640. Patented Jan. 1,1918.

F .1 l 1.2 f y ,11 H 4 f/ F9 0 Z ff/f VWL o k j y Wbb/woes .5l/wa Mozv'UNITED sTATEs PATENT oEErcE.

RALPH F. CHATILLON, OE GREENBURG, NEW YCRK, ASSIGNOR TO JOI-IN CHATILLON8c SONS, A CORPORATION 0F NEW YORK.

SCALE.

Speccation of Letters Patent.

Patented J an. 1, 1918.

Application led Api-i124, 1912. Serial N o. 692,990. Y

To all whom t may concern.'

Be it known that I, RALPH F. CHATILLON, a citizen of the United States,residing at Greenburg, in the county of Westchester and State of NewYork, have invented certain new and useful Improvements in Scales, ofwhich the following is a full, clear, and exact specification.

This invention relates to scales, and has particular reference to meansfor compensating for temperature variations in spring balances.

In the ordinary well-known forms of spring balances, wherein the beam isconnected to one or more coil springs, and to the pointer throughmultiplying gearing, a slight variation in the resistance or tension ofthe spring due to variation of temperature will, by reason of themultiplied connection between the pointer and the beam, cause a materialvariation in the weight registered on the dial or scale by the pointer.It is the obj ect -of this' invention to combine a thermostat with ascale in such manner that the rack or other suitable gear element whichactuates the pointer will be varied in effective length as thetemperature varies, so that a given weight will produce the samemovement of the pointer on the dial or scale, independently of thetemperature of the spring. For example, as the temperature of a coilspring increases, its strength will diminish, so that a given weightwill stretch the spring more at the higher temperature than it will at alower temperature, thereby producing a greater movement of the pointerand indicating a greater weight. The reverse also holds true, such aspring scale not indicating in low temperature the true weight, thevariation increasing as the gear ratio between the beam and the pointerincreases. In spring scales of the rack and pinion type, such asspecifically shown herein, I propose to compensate for temperaturevariations by varying the angle between the pitch line of the rack andthe line of pull of the weight by means of a thermostat, so that as thetemperature increases these lines approach parallelism, thereby tendingto reduce the effective movement 0f the rack, and increasing this angleasy the temperature lowers and thereby increasing the movement of thepinion which is connected to the pointer.

As shown herein, I provide a dial or scale and pointer of any suitablewell-known form, which is actuated by a movable rack, the rack, insteadof being directly connected with the beam as heretofore, being connectedtherewith through a thermostat which in the form shown herein varies theposition of the rack on the gear independently of the pointer accordingto the temperature. As the angle between the pitch line of the rack andthe line of movement of the beam increases, a greater throw will begiven to the pointer, and vvice versa, the movement of the pointer for agiven movement of the beam being a minimum whenv the line of movement ofthe rack is parallelv to the line of movement of the beam. I havediscovered that this principle can be availed of in scales forcorrecting temperature variations, so that the weight registered willbeindependent of the temperature of the spring.

In the accompanying drawings, Figure 1 is an elevation of a scaleembodying the invention; and

Fig. 2 is an elevation partly in section.

1 represents a case of suitable form having a dial 2 provided with asuitable scale for registering weights. 3 represents the pointer carriedby a stud shaft l journaled in the hanger 5 carried by thecasing, theshaft 4l carrying the driving pinion 6. represents the beam, carryingthe bar 8, to which a hook, scale pan or the like is attached. The bar 8is suitably guided by the casing so as to have a substantially verticalmovement. 9, 9 represent coil springs attached to the beam 7 at thelower ends and to the frame 1 at the upper ends, as by links 10 havingheads 11 detachably engaging lugs 1Q. These parts are all well known andmay be varied in any desired manner.

13 represents the rack, which, when moved in a vertical direction,revolves the pinion 6 and the pointer 3, but this rack 13, instead ofbeing directly connected with the bar 8 as heretofore, is connectedtherewith indirectly through a thermostatically operated connection 15.The rack 13 is preferably pivotally connected at 14 to the bar 15 at theupper end, and the bar 15 is carried by the free end of a thermostatwhich consists, in the form herein shown, of an iron bar 17 and a brassbar 16 rigidly connected together, and at the lower end connected to thebar S. The upper end of the thermostat moves laterally to the right whenthe temperature increases,

and to the left when the temperature decreases, thereby moving the upperend of the rack relatively to the lower end. rlhe more the upper end ofthe rack 13 is moved to the left by decrease in temperature ot thethermostat, the greater arc Vof movement will be imparted to the pinion6 by a given weight, the pitch line of the rack forming the hypotenuseof a triangle whose vertical side is parallel to the line of movement ofthe bar 7. The more the rack is deflected to the right by increase intemperature, the less the angle at the apex of the triangle becomes, andconsequently less teeth of the rack will engage with the pinion during agiven movement of the bar 7. Briefly, the rack always forms thehypotenusc of the triangle and the thermostat varies the length of thishypotenuse, thus effecting the desired temperature correction in thescale. 18 is a guide for the lower end of the rack, and tending to holdit in engagement with the pinion. Various modifications and changes maybe made without departing from the scope of the invention.

Having thus described my invention, I declare that what I claim as newand desire to secure by Letters Patent is l. A scale comprising weightsupporting mechanism, indicating means, an operating pinion therefor, arigid rack for actuating said pinion, and a thermostat connecting theweight supporting mechanism and the rack for moving the rack bodilyaccording` to temperature and transmitting the actuating force betweenthe weight supporting mechanism and the pinion.

2. A scale comprising a weighing spring, a weight supporting membercarried by said spring, weight indicating means, an operating pinionthere'tor, a rigid rack for rotating said pinion, and connections inpart rigid and in part thermostatic connecting the weight supportingmechanism and the rack for moving the rack bodily according totemperature and transmitting the actuating torce between the weightsupporting mechanism and the pinion.

3. A scale comprising a spring, a movable beam'connected to the spring,a pointer having an operating pinion, a movable gear element foractuating said pinion, and a thermostat connecting the beam and saidmovable gear element for maintaining a predetermined movement of thepointer with a movement of the gear element varying with thetemperature.

et. A scale comprising a spring, a movable beam connected to the spring,a pointer having an operating pinion, a rigid rack and meshing with saidpinion, and a thermostat for automatically moving the rack angularlyrelatively to the pinion.

5. A scale comprising a spring, a movable beam connected'to the spring,a pointer having an operating pinion, a rack engaging the pinion, and athermostat connected to the beam and to the opposite end of the rack.

ln testimony whereof l aiiix my signature,

lin presence of two witnesses.

RALPH F. CHATILLON. Witnesses J. S. VoosTER, G. N. KERK.

Copies of this patent may be obtained for five cents each, by addressings,the Gommssoner of Patents,

Washington, D. C.

